<!DOCTYPE HTML>
<html>
<!--
https://bugzilla.mozilla.org/show_bug.cgi?id=1175585
-->
<head>
  <title>Test for Bug 1175585</title>
  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
  <script type="text/javascript" src="/tests/SimpleTest/EventUtils.js"></script>
  <script type="application/javascript" src="/tests/SimpleTest/paint_listener.js"></script>
  <script type="application/javascript" src="apz_test_native_event_utils.js"></script>
  <script type="application/javascript" src="apz_test_utils.js"></script>
  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
  <style>
  #outer-frame {
      height: 500px;
      overflow: scroll;
      background: repeating-linear-gradient(#CCC, #CCC 100px, #BBB 100px, #BBB 200px);
  }
  #inner-frame {
      margin-top: 25%;
      height: 200%;
      width: 75%;
      overflow: scroll;
  }
  #inner-content {
      height: 200%;
      width: 200%;
      background: repeating-linear-gradient(#EEE, #EEE 100px, #DDD 100px, #DDD 200px);
  }
  </style>
</head>
<body>
<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1175585">APZ wheel transactions test</a>
<p id="display"></p>
<div id="outer-frame">
    <div id="inner-frame">
        <div id="inner-content"></div>
    </div>
</div>
<pre id="test">
<script type="application/javascript;version=1.7">

function scrollWheelOver(element, deltaY, testDriver) {
  synthesizeNativeWheelAndWaitForScrollEvent(element, 10, 10, 0, deltaY, testDriver);
}

function* test(testDriver) {
  var outer = document.getElementById('outer-frame');
  var inner = document.getElementById('inner-frame');
  var innerContent = document.getElementById('inner-content');

  // Register a wheel event listener that records the target of
  // the last wheel event, so that we can make assertions about it.
  var lastWheelTarget;
  var wheelTargetRecorder = function(e) { lastWheelTarget = e.target; };
  window.addEventListener("wheel", wheelTargetRecorder);

  // Scroll |outer| to the bottom.
  while (outer.scrollTop < outer.scrollTopMax) {
    yield scrollWheelOver(outer, -10, testDriver);
  }

  // Verify that this has brought |inner| under the wheel.
  is(lastWheelTarget, innerContent, "'inner-content' should have been brought under the wheel");
  window.removeEventListener("wheel", wheelTargetRecorder);

  // Immediately after, scroll it back up a bit.
  yield scrollWheelOver(outer, 10, testDriver);

  // Check that it was |outer| that scrolled back, and |inner| didn't
  // scroll at all, as all the above scrolls should be in the same
  // transaction.
  ok(outer.scrollTop < outer.scrollTopMax, "'outer' should have scrolled back a bit");
  is(inner.scrollTop, 0, "'inner' should not have scrolled");

  // The next part of the test is related to the transaction timeout.
  // Turn it down a bit so waiting for the timeout to elapse doesn't
  // slow down the test harness too much.
  var timeout = 5;
  yield SpecialPowers.pushPrefEnv({"set": [["mousewheel.transaction.timeout", timeout]]}, testDriver);
  SimpleTest.requestFlakyTimeout("we are testing code that measures actual elapsed time between two events");

  // Scroll up a bit more. It's still |outer| scrolling because
  // |inner| is still scrolled all the way to the top.
  yield scrollWheelOver(outer, 10, testDriver);

  // Wait for the transaction timeout to elapse.
  // timeout * 5 is used to make it less likely that the timeout is less than
  // the system timestamp resolution
  yield window.setTimeout(testDriver, timeout * 5);

  // Now scroll down. The transaction having timed out, the event
  // should pick up a new target, and that should be |inner|.
  yield scrollWheelOver(outer, -10, testDriver);
  ok(inner.scrollTop > 0, "'inner' should have been scrolled");

  // Finally, test scroll handoff after a timeout.

  // Continue scrolling |inner| down to the bottom.
  var prevScrollTop = inner.scrollTop;
  while (inner.scrollTop < inner.scrollTopMax) {
    yield scrollWheelOver(outer, -10, testDriver);
    // Avoid a failure getting us into an infinite loop.
    ok(inner.scrollTop > prevScrollTop, "scrolling down should increase scrollTop");
    prevScrollTop = inner.scrollTop;
  }

  // Wait for the transaction timeout to elapse.
  // timeout * 5 is used to make it less likely that the timeout is less than
  // the system timestamp resolution
  yield window.setTimeout(testDriver, timeout * 5);

  // Continued downward scrolling should scroll |outer| to the bottom.
  prevScrollTop = outer.scrollTop;
  while (outer.scrollTop < outer.scrollTopMax) {
    yield scrollWheelOver(outer, -10, testDriver);
    // Avoid a failure getting us into an infinite loop.
    ok(outer.scrollTop > prevScrollTop, "scrolling down should increase scrollTop");
    prevScrollTop = outer.scrollTop;
  }
}

SimpleTest.waitForExplicitFinish();

// Disable smooth scrolling because it makes the test flaky (we don't have a good
// way of detecting when the scrolling is finished).
pushPrefs([["general.smoothScroll", false]])
.then(waitUntilApzStable)
.then(runContinuation(test))
.then(SimpleTest.finish);

</script>
</pre>

</body>
</html>
